reCAPTCHA is a Turing test. Any test designed to work out whether one is interacting with a robot or a human is refered to as a Turing test.
I completely agree reCAPTCHA is a pain, the distortions are over the top and people struggle.
On my site I have two fields, one asks for "four plus 3". The next asks "now add 2". It would take a very clever bot to work out that "now add 2" is related to the previous question.
If you would like to do the same...
Add a new item as follows...
System name: Human
Caption: What is four plus 3
Type: Number
Mandatory: yes
Minimum Value: 1
Maximum Value: 9
Unique: No
Check:return strtolower($arg0) == '7';
Default Value: 0
All Messages: You didn't provide the correct answer. It's the number after 6.
Then add another new item...
System name: Now_Add
Caption: Now add 2
Type: Number
Mandatory: yes
Minimum Value: 1
Maximum Value: 9
Unique: No
Check: return strtolower($arg0) == '9';
Default Value: 0
All Messages: You didn't provide the correct answer. It's the number before 10.
Remove the reCAPTCHA item.
Clear cache.
Since this is on the subject of security; how can I replace the captcha with a turing test? Much easier for members to understand; I had one person to let me have it in an email because they could not understand the captcha. I use a turing test on my blogging site and it stops the bots just as well. Human spammers? They get by the captcha as well as the turing test. I looked in the market for a mod for this but could not locate one. What would be nice is a rotating list of questions that can be set up in the admin that will be randomly selected for the join form and other areas of the site that currently uses captcha.